I was working on a USA car today that was made in 1984 and that small diameter rubber hose to the EGR cooler was on there was sturdy - I had to cut it off and pull and tug on it and it was so strong I regret replacing it.

I've never seen anyone post here that the heater hose went - you know the ones that go through the firewall and probably take 7 hours to replace.

That very hose blew, and the car was lost because of it. all the water came out, and I was at highway speeds on the I-state. Engine overheated, and it was never right again. This was on my first 4000, an '83.

Refreshing this hose won't hurt. I've changed it on every 4000 since.

This was on my 85 4000S before I sold it. Got a nice split in one of the hoses from the heater core to the head. Tough to get at without removing half of the center console :(.
Took a while to do, plus it was raining outside.

I just probably had to remove the plastic ducting to the vents and I would have seen the heater core.